1. Field of the Invention
The present invention relates to a device for changing the electric wires and method for distributing power without cutting off power supply during the replacing work of the live electric lines on the electric poles, relocating work of the electric poles and alteration work of the power distribution route. The replacing operation of live electric wires is sequentially carried out by connecting the new wire and separating the old wire by the wire changing device mounted on each electric pole without using a bypass cable.
2. Related Prior Art
With rapid increase of power demand, power facilities to satisfy this demand are being expanded continuously. As the level of user needs for the quality of electricity increases, even an instantaneous service interruption becomes the target of a civil disruption, and electricity users' group activities and judicial cases are being increased. To supply power of good quality during power distribution maintenance, the uninterruptible method is preferred, in which the distribution maintenance is performed in the state where the power is not interrupted.
The previous distribution maintenance procedures using the uninterruptible method include a movable transformer truck type construction method, a bypass cable method and a breaking switch method for construction. In the bypass cable method, one of the temporary power transmission methods, a distribution maintenance is completed by having a cable required for a work area, a construction breaking switch, a movable transformer truck, a hot line bucket truck and a set of pneumatic actuators for hot line work, bypassing the supplied power using a bypass cable on the ground, performing removal and relocation tasks on a distribution line and then removing the bypass cable.
Moreover, in the case where the distribution line has an electric capacity of more than 5,000 KW, since the permissible capacity of a cable in the previous bypass cable method is under 5,000 KW, this wastes a lot of time and labor cost for switching the power load to another distribution line in order to reduce the load of the distribution line to less than 5,000 KW. Because a large capacity distributing method is used commonly, part of the load is switched and only the load of 5,000 KW is put into use uninterruptibly. This results in an insufficient effect of investment money and there occurs a serious problem in effectively operating the distribution network. In addition, it is impossible to construct a distribution line with more than two lines, i.e. upper and lower lines, per one pole by the existing temporary power transmission type interruptible method.
Therefore, for the above-described previous distribution maintenance using the uninterruptible method, a lot of construction workers are required. Also, a large number of temporary connection points of an extra high voltage, which are very dangerous, are made in order to install a bypass cable with a specified length of 50 m. This requires the use of protective equipment for connection failures and connection points. Because installation and removal tasks have to be repeated often, a lot of labor cost is required and the damage to the bypass cable is accelerated, thus threatening safety. If there occurs an accident or unexpected interruption, this costs a great deal, thus making it difficult to secure a good electricity quality. Also, this may cause more civil applications, economic losses and loss of life. Moreover, excessive load switching operations make the functioning of the distribution network unstable and the upper end line of a distribution line with more than two lines cannot be serviced with the uninterruptible method.